Buffering Phenol: pH directly

Jim Owens writes:
> I have heard that it is possible to measure the pH of an organic solution,
> but a pH meter or the pH papers will not give an accurate measure.
It is indeed.
For Phenol:
Mix 2 ml of organic phase with 8 ml of methanol and 10 ml of water. Use
a pH meter.
For Phenol/CIA:
Mix 2 ml of organic pahse with 5 ml methanol and 13 ml of water.
I think the problems mentioned contribute greatly to the variability of
organic extractions. I prefer to substitute a Proteinase K digest for
phenol extraction whenever feasible.
Jim
J. E. Graham
Biology and Chemistry Departments
Indiana University Bloomington